Ishin-Den-Shin system plays spoken messages through your finger

Forget using tape recorders and smartphones to play back spoken messages – what if you could simply hear them through a finger? Disney researcher Ivan Poupyrev has come up with a system that allows for just that. Using the human body as a sound transmitter, the technology lets you hear audio messages when someone touches your ear with their finger. Even more strikingly, it also lets you hear those spoken messages off the surface of any ordinary object you might touch, like a knife or a ring.

The system uses a very different principle from the wearable FingerWhisper device we looked at a while back, that lets users hear a phone conversation through their bones by sticking a finger in their ear. Poupyrev calls his system Ishin-Den-Shin, after a Japanese phrase that roughly translates as "what the mind thinks, the heart transmits."

The technology employs a handheld microphone connected to a computer that begins recording as soon as it hears the person speak. The computer transforms the recording into a sound loop which is further converted into a harmless high-voltage (but, crucially, low-current) inaudible signal that's transmitted to the microphone's conductive casing.

The person holding the microphone becomes a human sound emitter, as the low-power recorded sound creates a modulated electrostatic field around them. When they touch an object or another person's ear with their finger, the finger along with the ear or object forms a speaker allowing the small sound vibrations to be heard. The person being touched hears the message in their ear.

Poupyrev, who has been exploring the idea of using the human body as both an interface and a data transmitter, likens the technology to a form of physical telepathy. He says that the project grew out of two earlier ones: Teslatouch, a tactile touchscreen display that lets users feel virtual elements (for example, feeling objects snap into place on screen) and Revel, a wearable device that adds artificial tactile sensations to everyday objects when touched (imagine feeling the texture of grass on a nature-based wall painting, for instance).

"We observed that it could work on human skin, and started wandering if we could enhance human-to-human communication somehow," Poupyrev tells Gizmag. Once started on Ishin-Den-Shin, the team built it up within a few months.

Poupyrev, who has been attempting to blend physical and digital worlds seamlessly through numerous projects, says his vision for Ishin-Den-Shin involves transforming everyday objects into interactive sound devices. The surface touched needs to be able to vibrate, and some work better than others, he says. "It is important that person’s hands are really dry," Poupyrev tells us. "The object has to have a thin layer of dialectric on top for this to work."

The signal you hear in your ear isn't very loud, he adds. It's also possible for the sound to transmit itself through three or four people as long as their bodies are in contact with each other. For example, the third person in a line can touch their finger to the fourth person's ear, letting them hear a message, if the rest are holding hands as the first person speaks into the microphone. "The electrical field goes though the peoples' bodies," Poupyrev tells Gizmag. "The signal degrades after three or four people."

Poupyrev declined to discuss possible applications for the technology or how and when we might see it in the future. Olivier Bau and Yuri Suzuki were also part of the Pittsburgh-based Disney Research team that developed Ishin-Den-Shin. The project won an Honorary Mention at ARS Electronica’s PRIX ARS 2013 at Linz, Austria.